body {
    font-family: Arial, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}
.container {
    border: 1px solid #ccc;
    padding: 20px;
    border-radius: 5px;
    margin-bottom: 20px;
}
input, button {
    padding: 10px;
    margin: 5px;
}
iframe {
    width: 100%;
    height: 300px;
    border: 1px solid #ddd;
}